Polarized targeting of DNER into dendritic plasma membrane in hippocampal neurons depends on endocytosis
Polarized targeting of DNER into dendritic plasma membrane in hippocampal neurons depends on endocytosis
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DOI：
10.1111/j.1471-4159.2010.06714.x
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发表时间：
2010-06-01
影响因子：
4.7
通讯作者：
Kengaku, Mineko
中科院分区：
文献类型：
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作者：
Kurisu, Junko;Fukuda, Tetsuko;Kengaku, Mineko
膜蛋白靶向轴突和树突对于特定神经回路内的定向信号传递至关重要。许多树突状蛋白质已经被证明可以到达体树突膜的基础上选择性分选和运输的载体囊泡。利用培养的大鼠海马神经元，我们研究了Delta/Notch样EGF相关受体（DNER）的转运途径，DNER是一种跨膜Notch配体，在CNS树突中特异性表达。DNER胞质结构域的突变取消体树突定位也增加了其表面表达。此外，内吞作用的抑制导致DNER的体树突定位的破坏，表明DNER的体树突靶向依赖于内吞作用。DNER胞质结构域通过近端酪氨酸基序和中间结构域中的40个氨基酸延伸段结合网格蛋白衔接蛋白复合物-2，但不通过C-末端尾结合。分子和药理学抑制表明DNER的表面表达受网格蛋白依赖性和非依赖性内吞作用的调节。相反，DNER的体树突靶向主要通过DNER的C-末端尾由网格蛋白和衔接蛋白复合物-2-独立的内吞作用调节。我们的数据表明，网格蛋白独立的内吞作用是至关重要的体树突状蛋白的极化靶向。
P>The targeting of membrane proteins into axons and dendrites is of critical importance for directional signal transmission within specific neural circuits. Many dendritic proteins have been shown to reach the somatodendritic membrane based on selective sorting and transport of carrier vesicles. Using rat hippocampal neurons in culture, we investigated the trafficking pathways of Delta/Notch-like EGF-related receptor (DNER), a transmembrane Notch ligand which is specifically expressed in CNS dendrites. Mutations in the cytoplasmic domain of DNER that abolished somatodendritic localization also increased its surface expression. Furthermore, inhibition of endocytosis resulted in disruption of the somatodendritic localization of DNER, indicating that the somatodendritic targeting of DNER is dependent on endocytosis. The DNER cytoplasmic domain binds to a clathrin adaptor protein complex-2 via a proximal tyrosine motif and a 40 amino acid stretch in the mid-domain, but not by the C-terminal tail. Molecular and pharmacological inhibition revealed that the surface expression of DNER is regulated by clathrin-dependent and -independent endocytosis. In contrast, the somatodendritic targeting of DNER is predominantly regulated by clathrin- and adaptor protein complex-2-independent endocytosis via the C-terminal tail of DNER. Our data suggest that clathrin-independent endocytosis is critical for the polarized targeting of somatodendritic proteins.